compositing/repaint/iframes/compositing-iframe-scroll-repaint.html is flakey (maybe only with the patch from bug 90342).
When it breaks, the compositing layer already has a repaint, so in GraphicsLayerCA::setNeedsDisplayInRect() the dirty rects already contain the rect and we bail.
This suggests that testRunner.displayAndTrackRepaints() isn't triggering paints in all compositing layers in WK1; need to see if we're flushing layers at all in that code path.
The following tests were marked flaky in Mojave WK1
It looks like we never get a -viewWillDraw after the load event and before zero-delay timers, which is controlled by whether runloop observers fire at that time; they may not if there is no idle phase in the runloop.
Created attachment 354069 [details]
Comment on attachment 354069 [details]
Attachment 354069 [details] did not pass ios-sim-ews (ios-simulator-wk2):
New failing tests:
Created attachment 354077 [details]
Archive of layout-test-results from ews121 for ios-simulator-wk2
The attached test failures were seen while running run-webkit-tests on the ios-sim-ews.
Bot: ews121 Port: ios-simulator-wk2 Platform: Mac OS X 10.13.6
*** Bug 189841 has been marked as a duplicate of this bug. ***
*** Bug 189752 has been marked as a duplicate of this bug. ***